possum_risk_score: POSSUM Score for Operative Morbidity and Mortality Risk

In cliot: Clinical Indices and Outcomes Tools

POSSUM Score for Operative Morbidity and Mortality Risk

Description

Calculates the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM). This system predicts the risk of morbidity and mortality in surgical patients based on 12 physiological and 6 operative factors.

Usage

possum_risk_score(age, cardiac_signs, respiratory_signs, systolic_bp, pulse, gcs,
                  hemoglobin, wbc_count, urea, sodium, potassium, ecg_status,
                  operative_severity, multiple_procedures, total_blood_loss,
                  peritoneal_soiling, malignancy_status, mode_of_surgery,
                  urea_units = "mg/dL")

Arguments

age	Numeric. Patient age in years.
cardiac_signs	String. "normal", "mild" (diuretics/digoxin/angina/HTN), "moderate" (peripheral edema/warfarin), "severe" (raised JVP/cardiomegaly).
respiratory_signs	String. "normal", "mild" (dyspnea on exertion/COPD), "moderate" (limiting dyspnea), "severe" (dyspnea at rest/fibrosis).
systolic_bp	Numeric. Systolic blood pressure in mmHg.
pulse	Numeric. Pulse rate in bpm.
gcs	Numeric. Glasgow Coma Scale score (3-15).
hemoglobin	Numeric. Hemoglobin level in g/dL.
wbc_count	Numeric. White blood cell count in x10^9/L.
urea	Numeric. Blood Urea Nitrogen (BUN) or Urea.
sodium	Numeric. Serum Sodium in mmol/L.
potassium	Numeric. Serum Potassium in mmol/L.
ecg_status	String. "normal", "afib_mild" (AF rate 60-90), "abnormal_rhythm" (>4 ectopics/min, Q waves, ST changes).
operative_severity	String. "minor", "moderate", "major", "major_plus".
multiple_procedures	String. "1", "2", ">2".
total_blood_loss	Numeric. Total blood loss in mL.
peritoneal_soiling	String. "none", "minor" (serous fluid), "local_pus", "free_bowel_content" (or generalized pus/blood).
malignancy_status	String. "none", "primary" (primary only), "nodal" (nodal metastases), "distant" (distant metastases).
mode_of_surgery	String. "elective", "emergency_gt_24h" (resuscitation possible), "emergency_2_24h" (operation needed <24h), "emergency_lt_2h" (immediate surgery).
urea_units	String. "mg/dL" (default) or "mmol/L".

Value

A list containing:

Physiological_Score	The calculated physiological score (Range 12-88).
Operative_Severity_Score	The calculated operative severity score (Range 6-48).
Predicted_Mortality_Risk	Estimated percentage risk of mortality.
Predicted_Morbidity_Risk	Estimated percentage risk of morbidity.

References

Copeland GP, Jones D, Walters M. POSSUM: a scoring system for surgical audit. Br J Surg. 1991;78(3):355-360. doi:10.1002/bjs.1800780327

Examples

possum_risk_score(
  age = 70,
  cardiac_signs = "mild",
  respiratory_signs = "normal",
  systolic_bp = 140,
  pulse = 80,
  gcs = 15,
  hemoglobin = 13.5,
  wbc_count = 8.0,
  urea = 20,
  sodium = 140,
  potassium = 4.2,
  ecg_status = "normal",
  operative_severity = "major",
  multiple_procedures = "1",
  total_blood_loss = 400,
  peritoneal_soiling = "none",
  malignancy_status = "primary",
  mode_of_surgery = "elective"
)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.